Just another point i had 6 Bio BB's in a cup of water after 6 hrs they showed no signs of swelling or breaking down i even cut one in half and still nothing the breakdown doesnt seem to occure till around the 12-15hr mark fully submerged and even then i was still able to shoot them with ease. They didnt foul, jam or leave anykind of residue in the barrel.(KEWL) now that being said i dont suggest submerging these and shooting them this was just for testing purposes.